Fuel indicator



Nov. 12, 1935. 5 WATTELLS 2,020,593

FUEL INDICATOR Filed July 14, 1934 Patented Nov. 12, 1935 UNITED STATESPATENT OFFICE Claims.

My invention relates to .fuel indicators more particularly as applied tomotor cars, and the present embodiment is an improvement over thestructure covered in my pending patent applica- 5 tion, Serial Number691,859, filed October 2, 1933.

One object of the improvement is to materially simplify the mechanismincident to the indicator.

Another object of the improvement is to provide an alternative structurein the zone where the vital change in operation occurs, whereby toaccelerate such change.

With the above objects in view, reference is had to the accompanyingdrawing, in which Fig. 1 is an elevation of a typical motor car showingthe application of the improved indicator by means of dotted lines;

Fig. 2 is an enlarged group assembly of the units mainly involved in thedevice; and r Fig. 3 is a section of the main unit.

As stated in the previous case, it is customary for many motor cars tohave a fuel gauge on the dash. Frequently such gauge is inefficient ormisleading as to the actual amount of fuel in 5. the tank, so that thecar may run out of fuel when least expected or when it is far to thenext filling station. To avoid this kind of an occurrence, many driversare obliked to make frequent inspections or tests of the fuel level inthe tank,

39 or to carry spare fuel containers. In order to avoid the above risksor precautions, I have designed the improved fuel indicator to give adistinct warning to the driver in plenty time to reach a fuel station,and so construct the device 35 that it can never fail.

In accordance with the foregoing objects, specific reference to thedrawing indicates the motor car at l, its main fuel tank at I l, itsfuel suction pump at l2, and the fuel line from the main tank to thelatter at l3.

In carrying out the improvement, I provide a companion air line IA oftubing trained for a considerable distance immediately along the fuelline [3. As seen in Fig. 2, the two lines I3 45 and [4 pass downwardlyinto the tank II and make communication with the top portion of achamber l5 located in the lower portion of the fuel tank 12. As seen inFig. 3, the chamber I5 is a hollow body of firm construction, and has a50 lateral outlet near the bottom from which a short piece of tubing Itextends to the bottom of the fuel tank I2.

The tubing line l4 only extends in forward direction to a point belowthe dash, where it rises as indicated in Fig. 1, to enter the wall of atube H extending forward from the dash l8 and being suitably secured tothe latter by a frontal nut Hla or other means. The tube l'i has aperforation Ila to receive the tube 1 4, and another perforation llbdiametrically opposite the first one. 5 Within the tube I1 is slidable aplunger IS, the latter having a hand knob I9a on the front of the dashand being perforated crosswise at [922. The parts just described appearin their normal positions in' Fig. 2, the perforation I91) register- 10ing with the perforations Ila and I'll). Thus, a direct connection forthe entry of atmospheric air into the tube M is had. However, should theplunger knob I9a be drawn out some distance, this connection will be cutoff. 15 The novel indicator is not intended to function as long as asuflicient amount of fuel is had in the tank. The position of thechamber I5 is so calculated that the fuel below its connection with thetube [6 is considered as a reserve and to be 20 drawn upon when the fuelhas fallen to the level of such connection. With the level of fuel asindicated in Fig. 2, it will be apparent that the bottom openings of thelines I 3 and M will be bridged by fuel, since a liquid finds its ownlevel.

However, should the demand of fuel in line l3 deplete the supply to thepoint where the openings of the lines intothe chamber it are out ofcontact with the fuel, then the suction line 13 will begin to drawatmospheric air from the air line I4 by reason of its open condition inthe region of the dash, as previously described. This action will causethe fuel charge to the motor to become lean, and the motor willtherefore run irregularly and eventually stop, indicating to the driverthat something is wrong with the fuel supply. On drawing the dash knobI9a outward, the atmospheric air supply to the line l4 will be cut off,and the motor will begin to draw fuel from the reserve line 16 andresume regular operation, proving that the motor disability was due toshortage of fuel. At the same time, the projected po sition of the dashknob [9a will be an indication to the driver that the motor is runningon reserve fuel and a danger signal to stop at the nearest station andre-fuel. After this has been done, the knob 19a is pushed back to itsoriginal position, restoring the open entrance to the line [4.

The dash control treated in the present application is a simplificationof the one previously described, but it is understood that any type ofcontrol may be employed as long as it serves to open and close theentrance to the line H and act as an indicator when the reserve featureof the device is in use.

Theoretically, the fall of the tank fuel below the bottom openings ofthe lines I3 and I4 should at once establish an air by-pass orcommunication between them. However, I have found by extensiveexperiment that this does not occur, as the flow of the fuel into theline I3 by suction is so sustained that it prevailsdespite the loweringof the general level in the fuel tank, so that the indicating functiondoes not occur as one might properly expect, but is markedly delayed.For this reason, the improved indicator utilizes the chamber I5 toobtain a vertical differential between the entrance to the lines I3 andI4 and the reserve line I6. Thus, the continued fall of fuel in thechamber I5 gradually diminishes its connective tenacity, so to speak,between the reserve line I6 and the suction line I3, so that it soonbreaks down, permitting the air communication from the line I4. Theaction is also assisted by the fact that an increasing air pressureaccumulates in the chamber I5 as the fuel falls therein, tending tobreak up its continuity.

It is therefore seen that, by means of the chamber I5, I can calculatethe height of the reserve tube I6 to permit a sufficient amount ofreserve fuel to remain in the tank despite the delay in the responsivefunction of the indicator. Therefore, as far as the driver is concerned,the action is quite as automatic as in the previous case, but morepositive, since the action must occur within the vertical space betweenthe line' outlets and the reserve inlet, whereas in my previous case thelevel at which the function occurred proved by actual experimentspeculative.

In conclusion, it may be said that the improved indicator is, despitethe addition of the single part I5, extremely simple, yet more reliable.Also, the improvement does not require any change or alteration in themotor car equipment 7 in with the suction pipe line at a point above andrelatively close to the tank bottom, and a valve controlling said airsupply'pipe.

2. In combination, an internal combustion engine, a fuel tank therefor,a chambered vessel in said tank above its bottom, a suction pipe leadingfromthe vessel to the engine, a suction pipe leading from the bottom ofthe tank to the ves- 'sel, an air supply pipe communicating with saidVessel above the inlet of said pipe from the tank bottom, and a valvecontrolling said air supply pipe. 7

3. In combination, an internal combustion engine, a fuel tank therefor,a chambered vessel in said tank above and adjacent its bottom, a pipeleading from said vessel to the bottom of the tank, a suction pipeleading from the vessel to the engine, a valve controlled air supplypipe leading into the tank in communication with the vessel, and bothsaid suction pipe and air supply pipe opening to the vessel above theinlet of the pipe to the tank bottom.

4. In an automobile having a dash board, an engine and a fuel tanktherefor; a permanently open suction pipe line between said tank andengine and having a portion extending through the tank downwardly to itsbottom, a valve casing carried on the dash board, an air supply pipeleading from said valve easing into the tank and communicating thereinwith the suction line at a point above and relatively close to the tankbot: tom, and a valve plug movable in. said casing through the dashboard to control admission of air to said air supply pipe.

5. In an automobile having a dash board, an engine and a fuel tanktherefor; a permanently open suction pipe line between said tank andengine and having a portion extending through the tank downwardly to itsbottom, an air supply pipe having one end positioned adjacent said dashboard and leading thence into the tank and communicating therein withthe suction line at a point above and relatively close to the tankbottom, and said first named end of said air supply pipe being adaptedto be closed by the operator of the automobile to control admission ofair to said air supply pipe.

' FRANK S. WA'I'IELLS.

